Many therapeutic agents exhibit poor oral bioavailability and or absorption and therefore are administered by injection. For example, cephalosporin is the general term for a group of antibiotic derivatives of cephalosporin C, which is obtained from the fungus Cephalsporium acremonium. First generation cephalosporins and most second generation cephalosporins are functional in oral dosage forms. However, in many instances the third generation cephalosporins have poor oral bioavailability and therefore are often administered by injection.